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Miscellaneous. 289 



of the habits of the larva of Myrmtleon obsohfus, Say. Several of 



these grubs had been taken from the sandy soil of New Jersey durin 

 the month of July, and brought to the Academy at Philadelphia in 

 a large bowl. Their pits were of the usual character — an inverted 

 j hollow cone — but were sharper at the apex than usually represented. 



The pit is sometimes made by a backward movement of the grab 

 upon a spiral line which gradually closes upon the centre. The 

 body is just under the sand during this movement ; and the grains 

 of sand which fall upon the head are continually thrown upward bf 

 a sharp jerk of the head : this motion is somewhat lateral, not un- 

 like the " butting ' of a sheep or goat. 



A pit is also formed by the grub while stationary, the violent 

 ejection of the sand by the toss of the head causing a vortex to- 

 wards which the surrounding sand runs from all sides, thus naturally 

 forming the concavity. Within this the creature lies concealed, 

 and at once begins to toss the sand when the surface at the margin 

 is agitated by a crawling insect. Sometimes the head and jaws are 

 exposed ; they are laid l!at (as observed in these cases at least), ex- 

 tending horizontally, and not vertically upward as is usually shown 

 in figures. The habit may vary in this respect. 



Dr. McCook believed that the popular impression that the grub 

 throws sand after or at an ant when it appears to be escaping from 

 the pit is without foundation in fact. The sand is thrown up more 

 or less violently, so vigorously at times that it appears to boil. This 

 motion causes agitation of the superincumbent sand, which begins 

 to move toward the centre, carrying the ant with it into the jaws 

 of the grub. The sand was tossed up with force enough to throw 

 it out of the bowl to the distance of seven inches on the table, even 

 pellets as large as grains of rice being thus ejected ; but it tiew in 

 all directions, on the side opposite the ant or upon the ant, quite 



indiscriminately. 



The smallest ants introduced had great difficulty in moving over 



the wall of the pit, as the sand crumbled and rolled away from be- 



| neath even the light emmet-tread. One ant which escaped had a 



little ball of minute pellets attached to a hind foot, as though caused 

 to adhere by moisture or some viscid substance within the pit. 

 Others had minute grains adhering to the delicate hairs of the bod} 

 at many points. The inquiry was suggested whether there is any 

 secretion or excretion from the grub which may produce this effect 

 and -o contribute to secure the victim. 



The ants show a strange fascination for the pit, even after they 

 I have escaped. A large carpenter ant (Camponotus pennsylvanicus) 



was seized, escaped, rushed out of the hole, then in and around it 

 again and again, as though verily dazed. There is a vast deal of the 

 <fc Paul Pry" in the emmet nature ; but the ants were rarely ob- 

 served to deliberately walk into the pit. They stopped upon the 

 edge, when they reached it in course of their rambles about the 

 bowl, threw up their antennae and waved them restlessly, sometimes 

 stretched a fore foot over the brink, sometimes retreated, sometimes 



Ann. & Mag. N. Hist. Ser. 5. Vol xL 20 



